amp tek pulse amplifier A275 amptek , inc . 6 de angelo drive, bedford, ma 01730 u.s.a. tel: +1 (781) 275-2242 fax: +1 (781) 275-3470 email: sales@amptek.com http://www.amptek.com features power 15 mw slew rate 100 v/s input noise 4 nv/ ? hz stable dc operation 200 mhz gain-bandwidth product high reliability screening radiation hard to10 5 rad(si) unity gain stable applications space instrumentation portable instrumentation nuclear instrumentation precision active filter design pulse shaping the A275 is a high performance hybrid differential op-amp developed as a pulse amplifier for spaceborne nuclear instrumentation. its low power dissipation (1 5 mw), high slew rate (100 v/s), and low input noise (4 nv/ ? hz), make it ideal for use in a wide range of op-amp applications. the A275 is packaged in a standard 14-pin hybrid dip. A275 input output compensation compensation +6v -6v bias adjust 10 11 12 13 14 1 2 3 6 7 8 4 9 5 50 47nf 50 > 3k 47nf < 5pf 50 figure 1. - connection diagram pin function 1 inverting input 2 non-inverting input 3 bias adjust to pin 4, (r > 3 kohm) 4 -vs direct 5 -vs through 50 ohms 6 compensation to pin 7, (c = 0 to 5 pf) 7 case and ground 8 output through 50 ohms 9 output direct 10 +vs through 50 ohms 11 +vs direct 12 - 14 compensation (leave open for gain < 10, short for gain > 10)
absolute maximum ratings supply voltage 8 v input voltage v s operating temperature -55 c to +125 c storage temperature -65 c to +150 c lead temperature range (soldering, 10 sec.) +300 c electrical characteristics v s = 6 v, t a = +25 c parameter symbol conditions min typ max units input offset voltage v os 2 5 mv input offset current i os 0.1 0.6 a input bias current i b 1.5 4 a input capacitance c in 4 pf differential input resistance r in 44 kohm common-mode input resistance r in 5 8 mohm common-mode rejection ratio cmrr 90 95 db common-mode input range ivr 4.5 v power supply rejection ratio psrr 60 db large-signal voltage gain @5khz @5khz @10mhz @10mhz a lfc a lf a hfc a hf compensated uncompensated compensated uncompensated 64 72 16 24 66 74 20 28 db pulse risetime (a v = 10) trc tr compensated uncompensated 15 9 22 15 ns output voltage swing v op v on positive negative +4.5 +4.7 -4.5 -4.5 v open loop output resistance r o 750 ohm output short-circuit current l osc source sink 11 -4 ma slew rate s rp s rn positive negative 65 35 100 57 v/s input noise voltage density e n 4 nv/ ? hz supply current i s 1.1 1.25 1.4 ma power consumption p d 15 mw
figure 2. - A275 gain & phase the A275 can be tested as a shaping amplifier by using the circuit shown in figure 3. the pc-275 test board will accommodate three (3) A275s and will produce a 5 -pole pulse with 1 s risetime (2.3 s peaking time). figure 3. - A275 pulse characteristics
+6v +hv -6v -6v +6v -6v +6v +6v -6v active baseline restoration 3-pole shaping 44mv/mev 440mv/mev 1.5v/mev 200ns time to peak A275 9 2 1 7 5 14 13 12 10 jfet solid state detector 10nf (hv) 100m 10nf (hv) 1m a250 9 13 14 7 5 10 3m (pole-zero) 100pf (npo) 1.07k 8.87k 1.10k A275 9 2 1 7 5 14 13 12 10 8.87k 1.10k 47uh 168pf (npo) 866 output blr1 12 4 6 7 8 9 figure 4. - the a250 connected to a solid state detector with 3 -pole shaping and active baseline restoration. figure 5. - general case for 3 and 5 -pole response for different peaking times (t p )
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